A reactor core, of a nuclear reactor, is typically located in a containment vessel having predetermined operating pressure and temperature ranges for normal safe operation of the reactor. The containment vessel is typically provided with heat-transferring fluid coolant which is pumped into the containment vessel adjacent the reactor core, heated by the reactor core, with said heat being utilized in a steam turbine for the generation of electricity.
Under certain conditions, the heat-transfer fluid coolant to the core could be interrupted. In this event, the temperature of the core would continue to rise, resulting in a preliminary melting of the core, and upon uninterrupted continuous temperature increase, would cause a complete melt down of the core to a molten bolus of radioactive fuel. This fuel would flow by gravity downwardly from said core and could melt through the bottom of the containment vessel, causing great damage to the nuclear reactor and create extreme danger to public health and environmental safety.
Presently, known types of nuclear reactors can be provided with core melt down accepting fluxing or eutectic solute material or device beneath the core to receive the molten bolus of atomic fuel in the event of a melt down; however, presently there is no device which is retrofitable to the primary heat-transfer fluid system to automatically provide the containment vessel with a molten core fuel catcher. Moreover, no such safety device is provided in this manner through the heat-transfer fluid system or by a supplemental system connected to the containment vessel.